Determination of binding sites, affinity contents and capacity for human and rat Y and Z isolated from liver, kidney and small intestine as regard various organic anions of biological and clinical importance. Continued immunofluorescent localization of Y and Z in human and rat tissues with application of ferritin-conjugated antibody as well as peroxidase-conjugated antibody permitting subcellular localization of these proteins. Application of a newly developed radioimmunoassay for measurement of Y and Z in human liver, kidney and small intestine biopsy specimens permitting study of relationship of disease processes to these proteins. Study of the role of Y protein in renal organic anion transport. Localization of Z protein in plasma membrane from various tissues and further characterization of its role in fatty acid transport and esterification. Study of organic anion transport into vesicles of the endoplasmic reticulum particularly as regards the role of biotransformation in this process. Continued study of the inheritance and pathogenesis of various types of familial jaundice in man including recurrent jaundice of pregnancy, Gilbert's Syndrome, Dubin-Johnson Syndrome, Rotor Syndrome and benign familial recurrent cholestasis using newly developed tests of heterozygocity.